PDBsum entry 5kyh

Cell adhesion

PDB id: 5kyh

Contents

Protein chains

(+ 15 more) 242 a.a.

PDB id:

5kyh

Name:

Cell adhesion

Title:

Structure of iho670 flagellar-like filament

Structure:

Iho670. Chain: a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u. Fragment: unp residues 8-310. Engineered: yes

Source:

Ignicoccus hospitalis. Organism_taxid: 160233. Gene: igni_0670. Expressed in: ignicoccus hospitalis. Expression_system_taxid: 160233

Authors:

T.Braun,M.Vos,N.Kalisman,N.E.Sherman,R.Rachel,R.Wirth,G.F.Schroeder, E.H.Egelman

Key ref:

T.Braun et al. (2016). Archaeal flagellin combines a bacterial type IV pilin domain with an Ig-like domain. Proc Natl Acad Sci U S A, 113, 10352-10357. PubMed id: 27578865 DOI: 10.1073/pnas.1607756113

Date:

21-Jul-16 Release date: 07-Sep-16

Protein chains

A8AAA0  (A8AAA0_IGNH4) -  Archaeal Type IV pilin N-terminal domain-containing protein from Ignicoccus hospitalis (strain KIN4/I / DSM 18386 / JCM 14125)

Seq: 310 a.a.

Struc: 242 a.a.

DOI no: 10.1073/pnas.1607756113

Proc Natl Acad Sci U S A 113:10352-10357 (2016)

PubMed id: 27578865

Archaeal flagellin combines a bacterial type IV pilin domain with an Ig-like domain.

T.Braun, M.R.Vos, N.Kalisman, N.E.Sherman, R.Rachel, R.Wirth, G.F.Schröder, E.H.Egelman.

ABSTRACT

The bacterial flagellar apparatus, which involves ∼40 different proteins, has been a model system for understanding motility and chemotaxis. The bacterial flagellar filament, largely composed of a single protein, flagellin, has been a model for understanding protein assembly. This system has no homology to the eukaryotic flagellum, in which the filament alone, composed of a microtubule-based axoneme, contains more than 400 different proteins. The archaeal flagellar system is simpler still, in some cases having ∼13 different proteins with a single flagellar filament protein. The archaeal flagellar system has no homology to the bacterial one and must have arisen by convergent evolution. However, it has been understood that the N-terminal domain of the archaeal flagellin is a homolog of the N-terminal domain of bacterial type IV pilin, showing once again how proteins can be repurposed in evolution for different functions. Using cryo-EM, we have been able to generate a nearly complete atomic model for a flagellar-like filament of the archaeon Ignicoccus hospitalis from a reconstruction at ∼4-Å resolution. We can now show that the archaeal flagellar filament contains a β-sandwich, previously seen in the FlaF protein that forms the anchor for the archaeal flagellar filament. In contrast to the bacterial flagellar filament, where the outer globular domains make no contact with each other and are not necessary for either assembly or motility, the archaeal flagellin outer domains make extensive contacts with each other that largely determine the interesting mechanical properties of these filaments, allowing these filaments to flex.